Block B1 is a locality within Janakpuri, West Delhi, Delhi. Block B1 has a pincode of . Nearby localities of Block B1 include Block B1, Nangli Jalib, District Centre, Block B2, BB Block, Possangipur, Block B 3B, Chhoti Subji Mandi, Block A 5C, Block A3, Block B 3A, Block BE, Block BD, Shiv Nagar, Narang Colony, Block VA, Chander Nagar, Narang Colony, Gurunanak Pura, Virender Nagar, Shiv Nagar Extension, Block C2A, Block A3, Block A3, Block C2B, Block A 2B, Hari Nagar, Block VB, Asalatpur Village, Block C 4B, Block A 2A, Block BF, Block C2C, Block C1, Block AB, Block C 4E, Block C4F, Block A1, Block A2, Block A1B, Block C4G, Block C 2D, Block C3A, Block C-5A, Block C5D, RWA Colony, Janakpuri Institutional Area, Lajwanti Garden, Nangal Raya, Narang Colony, Block A 5B, Block A1A, C5B Block, Block C5B, Block C5C, Tihar Jail, Tihar Central Jail, Block C6B, Desu Colony, Pocket D 1, Gurjar Samrajya Chowk, Block B3, Janakpuri District Center, Prem Nagar, C-2 Block, Block C 4C, Block C 4D, Block C4H, Block C3, Block C 6A, D Block